Acting Superintendent Tim Beattie said violence would not be tolerated during the city's celebrations at the harbour and surrounds, and he warned troublemakers an undercover officer could be "standing right behind them" if they were looking to stir up trouble.

"Over the long weekend, there's going to be a strong police presence and we're going to focus heavily on anti-social behaviour and alcohol-fuelled violence," he said.

"We want to send the message to people who want to come to Wollongong and cause trouble, there's a fair chance the police will be just around the corner."

He said "well over 100" police would be working closely with Wollongong City Council and other agencies to keep the community safe at the weekend.

Police will also join council rangers to target illegal camping, which has become a problem at Stuart Park on public holidays.

New signage depicting the difference between a shade structure and a tent and specifying hours when shade structures are allowed is expected to go up today.

Lord Mayor Gordon Bradbery said people who ignored the restrictions would be fined.

"We've learnt the lesson from New Year's Eve and we're putting in stricter controls in terms of camping in Stuart Park," he said.

"There cannot be any tents or camping equipment brought into the area."

Australia Day is the council's biggest annual event, with more than 40,000 people expected to visit the harbour and surrounds for a program that starts with an aquathon at 8am and finishes with 9.30pm fireworks.

Last year, the popular event made the controversial citizens panel hit list, as it was suggested cutting one fireworks night a year would save $20,000. However, Cr Bradbery quashed any suggestion this year's Australia Day fireworks would be the last.

"I think there has to be a couple of celebrations in this city that the council has to get behind and New Year's Eve and Australia Day are, from my perspective, events we want to retain," he said.

Extra sponsorship might be sought to keep costs down.

Cr Bradbery reminded people that parking and access at Flagstaff Hill and its surrounds would be restricted on Australia Day, and he encouraged the use of "park and ride" or shuttle bus services, which would run until 11pm. A temporary paid car park will also be established on a section of Stuart Park for the Australia Day celebrations, run by Bulli Rural Fire Service, providing more than 150 extra parking spots.